lipids-propertiesclassificationfunction.pptx

explains about various types of lipids .
chemistry, classification , functions in the cells

1. LIPID CHEMISTRY AND CLASSIFICATION

2. Lipids are heterogeneous group of compound related to fatty acid, fats, oils, waxes and other related substances. The term lipid was first used by German biochemist ‘Bloor’ in 1943. It is derived from a Greek word ‘ lipos ’ means fat. Lipids are insoluble in water and soluble in organic solvent such as benzene, ether, chloroform, acetone etc. They yield fatty acids upon hydrolysis which are utilized by living organisms. Lipids is not a polymer as like carbohydrate and proteins.

3. It is macromolecules and major component of the diet because of their high energy value. The basic component of all lipid is fatty acid. The fats or lipids are defined as the esters of glycerol (alcohols) and fatty acids or as triglycerides. It is found in most plants and animals. In plants, lipids are mainly occur in seeds and fruits, whereas in animal, they are found in adipose tissue, bone marrow and nerve tissue

4. Triglycerides are the esters of Glycerol and Fatty acids

5. Alcohols are found in lipid molecule may be saturated. These commonly include glycerol, cholesterol, and higher alcohol. In the structure of glycerol, the carbon atom are denoted as 1, 2, 3 from any end. Glycerol A L C O H OLS:

6. Fatty acids are long chain organic acids having 4 to 30 carbon atoms. They have a single carboxyl group and a long, non polar hydrocarbon ‘tail’, which provide to most lipid their hydrophobic and oily nature.

7. Saturated fatty acids Unsaturated fatty acids Hydroxy fatty acids Cyclic fatty acids having single bond having double bond having hydroxyl group having ring structure

8. The general formula of these acids is C n H 2n+1 COOH. They tend to be solid at room temperature. They have single bond. I t m a y i n c rease b l o o d c h o l este r o l l e v el a n d c a r d i o v as c ular diseases. It may be divided in two groups: Straight chain fatty acids: found in plants and animals. Example: Stearic acid- CH 3 (CH 2 ) 16 COOH Palmitic acid- CH 3 (CH 2 ) 14 COOH Branched chain fatty acids: minor component of natural fat or oil. Ex amp l e : Isopalmitic acid- (CH 3 ) 2 CH(CH 2 ) 12 COOH Found in wool fat

9. 12 Number of C atoms Common Name Systemic Name Formula 2 Acetic acid Ethanoic acid CH3COOH 4 Butyric acid Butanoic acid CH 3 (CH 2 ) 2 COOH 6 Caproic acid Hexanoic acid CH 3 (CH 2 ) 4 COOH 8 Caprylic acid Octanoic acid CH 3 (CH 2 ) 6 COOH 10 Capric acid Decanoic acid CH 3 (CH 2 ) 8 COOH 12 Lauric acid Dodecanoic acid CH 3 (CH 2 ) 10 COOH 14 Myristic acid T etra d e canoic acid CH 3 (CH 2 ) 12 COOH 16 Palmitic acid Hexadecanoic acid CH 3 (CH 2 ) 14 COOH 18 Stearic acid O c tadec a no i c acid CH 3 (CH 2 ) 16 COOH 20 Arachidic acid Eicosanoic acid CH 3 (CH 2 ) 18 COOH 22 Behenic acid Doc B o io s ch a e n mi o str i y c fo a r m c e i d d ics C 6/ H 29/2 ( C 12 H ) COOH 3 2 20

10. S.No. Number of C atoms, number and location of double bonds F a m il y C o mm on Name S y s te m ic Name [A] M o n o en o i c acids (one double bond) 1. 16:1 ; 9 ω 7 Palmitoleic acid ci s -9- Hexadecenoic 2. 18:1;9 ω 9 Oleic Acid cis -9- O c tadec e no i c 3. 18:1;9 ω 9 Elaidic acid trans 9- Octadecano i c [B] Dienoic acids (two double b o n d s ) 1. 18:2;9,12 ω 6 Linoleic acid all- cis -9,12- 6/29/201 O 2 ctadecadie 1 n 8 o h

11. S.No. Number of C atoms, number and location of double bonds F a m il y C o mm on Name S y s te m ic Name [c] Trienoic acids (three double b o n d s ) 1. 18:3;6,9,12 ω 6 Y- Linolenic acid all- cis - 6,9,12 - O c tadec a tr i en o i c 2. 18:3;9,12,15 ω 3 α-Linolenic all- cis - 9,12 , 15O ctad ecatrienoic [ D ] T e t r ae n o i c acid(Four double bonds) 20:4 ; 5,8 , 11 , ω6 19 Biochem A is r t a ry c fo h r m id ed o ic n s ic 6/29/201 a 2 ll- cis -

12. S.No. Number of C atoms, number and location of double bonds F a m il y C o mm on Name S y s te m ic Name [E] P e n t ae n o ic acids (Five double b o n d s ) 1. 20:5;5,8,11,1 4,17 ω 3 Timn o d o n i c acid all- cis - 5,8,11,14,17 - E i cosa p enta enoic [ F ] H e xa e noic acid(Four double bonds) 22:6;4,7,10,1 3,16,19 ω3 Cervonic acid all- cis - 19- 6 / 29 / 2 1 4 2 ,7,10,13,1 6 2 , h

13. They have usually double bond. Unsaturated fats , which are liquid at room temperature, are beneficial fats because they can decrease blood cholesterol levels, stabilize heart rhythms, and play a number of other beneficial roles . Example: Oleic acid Linoleic acid Linolenic acid Arachidonic acid C n H 2n-1 COOH (Contain one double bond) C n H 2n-3 COOH (Two double bond) C n H 2n-5 COOH (Three double bond) C n H 2n-7 COOH (Four double bond)

14. Biochemistry for medics 6/29/2012 15

15. Trans fatty acids are present in certain foods, arising as a by-product of the saturation of fatty acids during hydrogenation, or "hardening," of natural oils in the manufacture of margarine. An additional small contribution comes from the ingestion of ruminant fat that contains trans fatty acids arising from the action of microorganisms in the rumen. Naturally-occurring unsaturated vegetable oils have almost all cis bonds, but using oil for frying causes some of the cis bonds to convert to trans bonds. Biochemistry for medics 6/29/2012 16

16. Phytanic acid present in butter Sebum also contains branched chain fatty acids There may be even or odd chain fatty acids. Even chain fatty acids are predominantly present. d) Cyclic fatty acids- Chaulmoogric acid and Hydnocarpic acid e) Substituted fatty acids Cerebronic acid- OH fatty acid c)Branched Chain Fatty acids 17

17. Short chain-with 2-6 carbon atoms Medium chain- with 8-14 carbon atoms Long chain- with 16-18 carbon atoms Very long chain fatty acids- with 20 or more carbon atoms Biochemistry for medics 6/29/2012 18

18. 1-Fatty acids are the building blocks of dietary fats. The human body stores such fats in the form of triglycerides . 2)- Fatty acids are also required for the formation of membrane lipids such as phospholipids and glycolipids. -They are required for the esterificaton of cholesterol to form cholesteryl esters. They act as fuel molecules and are oxidized to produce energy. Biochemistry for medics 6/29/2012 19

19. Polyunsaturated fatty acids such as Linoleic and Linolenic acids are essential for normal life functions. They are therefore characterized as essential fatty acids. Arachidonic acid is considered as semi essential fatty acid since it can be synthesized from Linoleic acid . Essential polyunsaturated fatty acids can be classified as belonging to one of two "families", the omega-6 family or the omega-3 family. Fatty acids belonging to these two families differ not only in their chemistry, but also in their natural occurrence and biological functions. Biochemistry for medics 6/29/2012 20

20. Components of cell membranes, structural elements of gonads and mitochondrial membrane Required for brain growth and development Precursors of Eicosanoids Play important role in vision They have a cardio protective role- Lower serum cholesterol and increase HDL levels Prevent fatty liver formation Deficiencies of essential polyunsaturated fatty acids may cause a wide variety of symptoms, including retarded growth in children, reduced fertility and pathologic changes in the skin. Biochemistry for medics 6/29/2012 21

21. CLASSIFICATION OF LIPID LIP I D Simple lipid Compound lipid Derived lipid Fat & Oils Wax Phospholipids Glycolipids Steroids Terpenoid T ri g l y c eri d es Beewax Lecithin Cephalins Phosphotidyl - inositol S phin g o m y elins Ce r eb r o si d es G an g lios i d es Monoterpene Diterpenes etc S te r ols

22. These are esters of fatty acids and alcohols. They are formed by the condensation of alcohols and acids. XH + HOC 2 H 5 XC 2 H 5 + H2O ( Acid + Alcohols Ester) For example natural fats and waxes are tri-esters of fatty acids and glycerol.

23. Fats are found in all living cells. They are formed from carbon, hydrogen and oxygen, but they are poor in oxygen in compare to carbohydrates. T h e y a r e inso l u b l e i n w a te r a n d s o l u b l e i n or g anic solvent. The fats, which are liquid at room temperature, are called oils. Lipids are high molecular weight compounds. The glycerol is trihydric alcohols, in which one, two or three – OH group react with fatty acids to form mono, di or triglycerides.

24. I n al l f a ts, g l y ce ro l i s pre s e n t , b u t t h e c o m p osit i o n of fatty acids may be different. The fatty acids may be saturated or unsaturated. In living cells, fat or its derivatives are present as main constituents of protoplasm. T h e y s e r v e a s sou r ce of e n e r g y an d e n ter s i n t h e composition of various cell components. Dou b l e e n e r g y i s r e l e a s e d f r o m a lipid m o l e cu l e than oxidation of glucose molecule. M o st anima l f a t suc h a s m ilk , m e e t , e g g s ar e r i c h in saturated fatty acids. P la n t ce l ls c o n tai n a la rg e p o r t io n of uns a tu r a te d f a tty acids.

25. These are the esters of long chain saturated and unsaturated fatty acids with monohydroxy alcohols. In vertebrates, waxes are secreted by cutaneous glands as a protective coating to keep the skin lubricated and water proof. Hair, wool and fur also coated with wax. The leaves of many plants are shiny because of the deposition of protective coating. Waxes also serve as the storage form of fuel in planktons. Waxes act as major food and storage lipid in marine organisms (whale, salmon), because they consume planktons in large amount. They are widely used in making varnishes, wax coated paper, lotion, oinments etc.

26. Compound lipid are those molecule which consist of glycerol and fatty acid join with other organic molecule such as carbohydrate, protein, amino acids etc. Compound lipid can be categorized in to two types: Phospholipid Glycolipid

27. Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group, and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue. The phosphate group can be modified with simple organic molecules such as choline, ethanolamine or serine. Phospholipids are a key component of all cell membranes. They can form lipid bilayers. The phospholipids are amphiphilic. The hydrophilic end usually contains a negatively charged phosphate group, and the hydrophobic end usually consists of two "tails" that are long fatty acid residues.

28. Lecithin is a fat that is essential in the cells of the body. It can be found in many foods, including soybeans and egg yolks. Lecithin is taken as a medicine and is also used in the manufacturing of medicines. Lecithin is used for treating memory disorders such as dementia and Alzheimer's disease. Lecithin is a any group of yellow-brownish fatty substances occurring in animal and plant tissues which are amphiphilic – they attract both water and fatty substances, and are used for smoothing food textures.

29. In addition to glycerol and 2 mol of fatty acids, lecithin also contain phosphoric acid and a nitrogen base choline. On hydrolysis, lecithin yields choline, phosphoric acid, glycerol and 2 mol of fatty acids.

30. Cephalins are phosphoglycerides that contain ehtanolamine or the amino acid serine attached to the phosphate group through phosphate ester bonds. Cephalins are found in most cell membranes, particularly in brain tissues. They have role in blood coagulation and accelerate blood clotting.

31. PI is classified as a glycerophospholipid that contains a glycerol backbone, two non-polar fatty acid tails, a phosphate group substituted with an inositol polar head group. The most common fatty acids of phosphoinositides are stearic acid, and arachidonic acid. Hydrolysis of phosphoinositides yield one mole of glycerol, two moles of fatty acids, one mole of inositol and one, two, or three moles of phosphoric acids, depending on the number of phosphates on the inositol rings. It is regarded as the most acidic phospholipids. It play important roles in lipid signaling, cell signaling and membrane trafficking.

32. It is also known as phosphosphingosides. These are commonly found in nerve tissue (myelin sheath). They are lack in plant and microorganisms. Sphingomyelin consists of a phosphocholine head group, a sphingosine, and a fatty acid. It is one of the few membrane phospholipids not synthesized from glycerol. The sphingosine and fatty acid can collectively be categorized as a ceramide. This composition allows sphingomyelin to play significant roles in signaling pathways: the degradation and synthesis of sphingomyelin produce important second messengers for signal transduction. 🞂

33. G l y c o lipids a r e lipids with a carbo h y d r at e a tt a c h ed b y a glycosidic (covalent) bond. Their role is to maintain the stability of the cell membrane and to facilitate cellular recognition. I t i s e s s e n t i a l to t h e im m u n e res p onse an d al l o w ce l l s to connect to one another to form tissues. Glycolipids are found on the surface of all eukaryotic cell membranes. The essential feature of a glycolipid is the presence of a monosaccharide or oligosaccharide bound to a lipid moiety. The most common lipids in cellular membranes are glycerolipids and sphingolipids, which have glycerol or a sphingosine backbones, respectively.

34. Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1- hydroxyl moiety. The sugar residue can be either glucose or galactose. Therefore the two major types are called glucocerebrosides and galactocerebrosides (galactosylceramides). Galactocerebrosides are typically found in neural tissue, while glucocerebrosides are found in other tissues. Glucosylceramide is a major constituent of skin lipids, it is the only glycosphingolipid common to plants, fungi and animals. Galactosylceramides have not been found in plants.

35. A ganglioside is a molecule composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (e.g. n-acetylneuraminic acid, NANA) linked on the sugar chain. The name ganglioside was first applied by the German scientist Ernst Klenk in 1942 to lipids newly isolated from ganglion cells of the brain. More than 60 gangliosides are known, which differ from each other mainly in the position and number of NANA residues. It is a component of the plasma membrane that modulates cell signal transduction pathways, growth and differentiation of tissues.

36. H y d r o l ys i s p r o d uct of s i mp l e an d c o mp o u n d lip i ds is called derived lipids. T h e y i n c l u de f a tt y a cid, g l y ce ro l , sph i n g osin e an d st e r oid derivatives. S te r oi d d e r iv a ti v es a re p h ena n th r e n e st r u c tu r es th a t a r e quite different from lipids made up of fatty acids.

37. Steroids are derived lipids because they are hydrophobic and insoluble in water, but they do not resemble lipids since they have a structure composed of four fused rings. Sterols such as cholesterol and ergosterols is the most common steroid and is the precursor to vitamin D, estrogen, progesterone, aldosterone, cortisol, and bile salts. Sterols also known as steroid alcohols. S te r ols of pla n t s a r e cal l ed p h yt o st e r ols an d st e r o ls of animal are called zoosterols. C h o l e s te r o l i s c o m m o n z o oste r ols a n d st i gma s te r o l is phytosterols. Er g oste r ols i s pre s e n t i n c e ll m emb r an e of f u ngi an d protozoa.

38. Cholesterol is widely distributed in all cells and is a major component of cell membrane and lipoproteins. Cholesterol is a C 27 compound with molecular formula C 27 H 46 O. With a hydroxyl group at C 3 and a double bond between C 5 and C 6 . An aliphatic side chain is attached at C 17 and 5 methyl groups. Cholesterol exists as crystals that are white, shiny. It has a high melting point of 150ºC. It is insoluble in water and soluble in fat solvents. Cholesterol oxidized under suitable conditions and to form a ketone called cholestenone. The hydroxyl group of cholesterol readily forms ester with fatty acids like stearic acid.

39. I t h elps i n ma i n tena n ce of o ur bo d y t emp e r a tu r e an d protects our internal organs. I n pharm a ce u tica l i n d u s tr i e s , c h o l e s te r o l i s use d i n t h e manufacture of steroid hormones and vitamin D.

40. The terpenoids, sometimes called isoprenoids, are a large and diverse class of naturally occurring organic chemicals derived from the 5-carbon compound isoprene, and the isoprene polymers called terpenes. Most are multicyclic structures with oxygen-containing functional groups. Terpenoids mostly occur in natural products and can be found in all classes of living things. Several terpenoids are biologically active and are exploited in the fight against cancer, malaria, inflammation, and a variety of infectious diseases . Terpenoids can be classify as monoterpene, diterpene, and polyterpene etc. Most common example are carotenoids, lycopene pigment etc.

41. Physical property: Lipids may be either liquids or non-crystalline solids at room temperature. Pure fats and oils are colorless, odorless, and tasteless. They are energy-rich organic molecules. Insoluble in water. S o l u b l e i n or g ani c s o l v e n t s li k e a l c o h o l , ch l o rof o rm, acetone, benzene, etc. No ionic charges. Solid triglycerols (Fats) have high proportions of saturated fatty acids. Li q uid tri g l y ce rols (Oils) h a v e hi g h p r oport i o n s of unsaturated fatty acids.

42. 1. Hydrolysis of triglycerols: Triglycerols like any other esters react with water to form their carboxylic acid and alcohol a process known as hydrolysis.

43. 2. Saponification: Triacylglycerols may be hydrolyzed by several procedures, the most common of which utilizes alkali or enzymes called lipases. Alkaline hydrolysis is termed saponification because one of the products of the hydrolysis is a soap, generally sodium or potassium salts of fatty acids.

44. 3. Hydrogenation: The carbon-carbon double bonds in unsaturated fatty acids can be hydrogenated by reacting with hydrogen to produce saturated fatty acids.

45. 4. Halogenation: Unsaturated fatty acids, whether they are free or combined as esters in fats and oils, react with halogens by addition at the double bond(s). The reaction results in the decolorization of the halogen solution. Stearate tetra iodinate

46. Lipids pl ay e x t r e m e l y import a n t r o l es i n t h e n ormal functions and structure of a cell membrane. It is used as energy storage and work as insulator. Used as a protective coating in plant leaves from drying up. Lipid act as hormones. Act as the structural component of the body and provide the hydrophobic barrier. Lipids a r e majo r sou r ces of e n e r g y i n an i mal s an d hi g h lipid containing seeds. Lipid act as chemical messengers between cells. L a y e r s of s u bcu ta n eous f a t u n d er t h e ski n als o h e l p in insulation and protection from cold.

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